Evaluation of brain function in acute carbon monoxide poisoning with multimodality evoked potentials

The median nerve somatosensory evoked potentials (SEP), pattern reversal visual evoked potentials (VEP), and brain stem auditory evoked potentials (BAEP) were studied in 109 healthy adults and in 88 patients with acute carbon monoxide (CO) poisoning. The upper limits for normal values of peak and interpeak latencies of multimodalities of evoked potentials in the reference group were established by a stepwise multiple regression analysis. SEP changes selectively affecting N32 and N60 were found in 78.8% of patients. There was prolonged P100 latency of VEP in 58.2% of the cases examined. The prevalence of BAEP abnormalities in comatose patients (36%) was significantly higher than that (8.6%) in conscious patients. BAEP abnormalities were most frequently seen in comatose patients who had diminished brain stem reflexes (77.8%). It has been found that a consistent abnormality involving N20 and subsequent peaks in SEP, a remarkable prolongation of P100 latency in VEP, or a prolongation of III-V interpeak latency in BAEP as well as the reoccurrence of evoked potential abnormalities after initial recovery all indicate unfavorable outcomes in patients with acute CO poisoning. The multimodality evoked potentials have proved to be sensitive indicators in the evaluation of brain dysfunction and in the prediction of prognosis of acute CO poisoning and the development of delayed encephalopathy.

Developmental changes of L-lysine-ketoglutarate reductase in rat brain and liver

1. Developmental aspects of L-lysine-ketoglutarate reductase, the first enzyme in saccharopine pathway of L-lysine degradation in rat liver and brain tissues were studied. 2. Although the adult rat brain shows negligible activity, the enzyme activity was shown to be highly active during the early stages of development. 3. The enzyme activity gradually decreased through development in the brain, whereas it gradually increased in the liver, establishing the fact that the saccharopine pathway is the major pathway in liver. 4. Our results also show that glucagon stimulated the induction of this enzyme by 2-3-fold in both adult liver and brain tissues.

[Pharmacokinetics of sinomenine by HPLC]

Pharmacokinetics of sinomenine in rabbit was studied by reverse-phase HPLC method. After i.v. injection of 20 mg/kg of sinomenine to rabbits, the pharmacokinetic characteristics were found to fit a two-compartment open model.

Highly polymorphic XbaI RFLPs of the human 21-hydroxylase genes among Chinese

A highly polymorphic XbaI restriction site flanking the human 21-hydroxylase genes (21-OHA and 21-OHB) was found with the probe pC21/3c, the cDNA of the 21-hydroxylase gene. From the results of RFLP analysis of 10 subjects with congenital adrenal hyperplasia (CAH) owing to 21-hydroxylase deficiency and their parents, at least four polymorphic fragments (30 kb, 27 kb, 25 kb, and 15 kb) resulting from cleavage at the polymorphic endonuclease sites outside the genes were found, and at least 10 different polymorphic patterns were observed among Chinese. These results indicate that these polymorphic loci are very informative for prenatal diagnosis of 21-hydroxylase deficiency.

Assessment of carotid artery stenosis by MR angiography: comparison with x-ray angiography and color-coded Doppler ultrasound

PURPOSE

To compare magnetic resonance angiography (MRA) with duplex Doppler ultrasound (US) and x-ray angiography (XRA) in the evaluation of the carotid bifurcation.

METHODS

The carotid arteries of 61 patients were studied using MRA, US, or XRA; 31 of the patients underwent all three examinations. MRA included both 2D and 3D time-of-flight sequences. Internal and external carotid artery origins were graded normal, mild, moderate, severe, or critical stenosis, or complete occlusion by each of the three studies.

RESULTS

Spearman rank correlations of both internal and external carotid artery grades were 0.85 (MRA and XRA), 0.69 (MRA and US), and 0.73 (XRA and US). For internal carotid artery origins only, the correlations were 0.94 (MRA and XRA), 0.85 (MRA and US), and 0.82 (XRA and US). Of discrepancies in internal carotid artery interpretation greater than one grade, seven resulted from US error, three from MRA error, and one from XRA error. A 2-cm partially thrombosed aneurysm detected by US and MRA was missed by XRA. Of 16 possible ulcers on XRA, 11 were noted by MRA, none by US.

CONCLUSIONS

MRA and XRA are similar in assessment of carotid bifurcation stenosis. MRA, like US, permits direct visualization of plaque. This preliminary study suggests that MRA may be used to clarify equivocal findings of US, or replace XRA in presurgical planning.

[Evaluation of a logistic regression model in predicting the prognosis of Graves' disease treated by antithyroid drugs]

One hundred and twelve new cases of Graves' disease were treated by tapazole for 6 months and followed up for another 12 months. The initial dose was 30 mg/d. Clinical and biochemical euthyroidism was achieved within 1 to 3 months, then a maintenance was given until cessation of drugs at 6 months. One hundred and eleven cases completed the study. Remission and relapse were defined at the end of follow-up for 1 year according to the presence or absence of clinical manifestation of hyperthyroidism and the levels of T3 and T4. The results of the 12-month follow-up showed that 46 of 111 cases were in remission, and the remaining 65 cases suffered relapse. A logistic regression model with 4 variables was established, which included thyroid suppression rate and goitre size by palpation at the end of drug treatment, the level of T3 before therapy, and the patients' age. The model had 81.5% sensitivity, 84.8% specificity and 82.9% (92/111) accuracy in predicting the outcome of Graves' disease after withdrawal of drug for 1 year. The results were much better than any other univariate analysis in this study.

[Detection of steroid 21-hydroxylase gene variation among normal Chinese and patients with congenital adrenal hyperplasia]

Genomic DNA from 40 unrelated healthy individuals and 16 families affected with 21-hydroxylase deficiency were digested with restriction enzyme Taq I followed by Southern blot and hybridization using a 21-hydroxylase (21-OH) gene cDNA probe. In healthy individuals the number of copies of 21-OHB gene was constant while that of 21-OHA gene was variable including deletion and duplication. In addition, we found an extra 5.6 kb band in one normal person and in one CAH family. Among the 16 affected families, 19% of 21-OHB gene were deleted. No homologous deletion was found. The frequency of deletion is lower than that reported in the literature. There was variation in the copy-number of 21-OHA gene among patients with CAH, yet no difference was found between the patients and normal persons. The information on prenatal diagnosis of CAH is briefly discussed.

[Investigation on the distribution and serotyping of V. parahaemolyticus isolated from marine products and environment in Zhoushan archipelago]

Isolation for V. parahaemolyticus from 1003 samples of marine products and environment was attempted in Zhoushan archipelago in 1986-1987. The results showed that V. parahaemolyticus could be detected from all kinds of marine products, the positive rate was between 40%-100%. The V. parahaemolyticus was detected in all samples from the environment. The main O groups were O2, O5, O1, O4, O3 and O12, the O9 groups was not detected. Although 103 serotypes have been detected, the main serotypes were O1K32, O5K17, O5K15, O2K28, O2K3 and O12K51(52), 17.9% of the strains could not be typed.

Identification of aortic thrombus by magnetic resonance imaging

The unique properties of magnetic resonance imaging result in the potential to differentiate various components of the diseased arterial wall. In this article four cases are presented in which magnetic resonance imaging showed mural aortic thrombus and its anatomic relationship to the visceral and renal arteries. Once thrombus is identified and localized specific operative strategies can be undertaken to prevent recurrent embolic events and/or avoid perioperative thromboembolic complications.